1. Field of the Invention
The present invention relates to a vehicle television using a diversity antenna, and more particularly, to a device and method for automatically changing a reception broadcast channel of a vehicle television with a diversity antenna when an image signal and a voice signal have much noises and the diversity antenna has many number of switching times.
2. Description of the Related Art
As an industrial technology develops and a general public's life is rich, a car becomes a necessity to general public. The general public increasingly spends a time in the car on business and/or to enjoy leisure. As the time spent in the car is increased, it is a trend that a vehicle car audio system is installed as a basic specification to relieve boredom during car driving, and a vehicle television is also much installed in recent years.
However, due to a characteristic of a vehicle, that is, due to vehicle's sequential turning while driving at a fast speed, it is difficult to receive a television broadcast signal while driving. In order to solve such a drawback, put on a market is being a vehicle television with a plurality of diversity antennas, for switching the antenna outputting a good quality of broadcast signal and receiving the broadcast signal with a different directionality.
The vehicle television determines a quality of the broadcast signal using a vertical sync signal of the broadcast signal for the same broadcast channel received through each of the diversity antennas, switches the antenna receiving the good quality of broadcast signal, and receiving the broadcast signal through the switched antenna.
As described above, the vehicle television receives the broadcast signal for the same broadcast channel. In case where, due to vehicle movement, the broadcast channel for the same broadcasting station is changed, thereby deteriorating the quality of broadcast signal or making it difficult to receive the broadcast signal, a driver should directly manipulate a channel key and search for the changed channel.
Due to this, the driver turns his/her eyes to the television during driving and therefore, there is a drawback of lack of driver's concentration and occurrence of a traffic accident.
In order to solve this drawback, there has been proposed a method in which a region using a different broadcast channel for the same broadcasting station is defined, a current position is measured using a global positing system (GPS), and a broadcast channel is automatically changed to the broadcast channel of the region corresponding to the measured position.
In case where the method uses the GPS, it is advantageous of automatically accurately changing the broadcast channel on a per-preset region basis, but has a drawback in that, even when a good quality of broadcast signal is substantially received at a boundary between regions, the broadcast channel is changed.